14. The usefulness of urine

Transcription

1 14. The usefulness of urine Urine has been used as a valuable plant food for centuries in many parts of the world, particularly in the Far East. It is surprising therefore that nearly all the urine produced in the West and in Africa goes to waste and is lost to agriculture. Each of us passes about 1.5 litres of urine every day - and almost to the last drop, it is either flushed down a toilet or enters a deep pit latrine. The fact is that urine is a very valuable product - in several ways. It contains a lot of nitrogen and also phosphorus and potassium in smaller quantities, nutrients which are very valuable to plant growth. Simply put, urine is too valuable to waste. The nitrogen found in abundance in urine is good for plant growth because it helps to build protoplasm, protein and other components of plant growth. It certainly promotes leafy growth. Leaves become more numerous, go greener and larger and more fleshy with urine application. Phosphorus is important in the root formation, ripening of fruits and germination of seeds, although the percentage of phosphorus compared to nitrogen in urine is low. Potassium is also essential for promoting good fruit (and flower) development. Plants differ in their requirements, but overall plants fed with some urine grow better than plants which never come into contact with urine. Urine is particularly valuable for grasses like maize and leafy green vegetables, and onions, which respond to the high nitrogen content of urine. Methods of collecting urine By far the simplest method of collecting and storing urine is for men to urinate in bottles when they visit the toilet. There are several other methods which can be used - the desert lily concept is one - where a funnel is mounted over a plastic drum in some position which allows the passing male to urinate in privacy. The simplest are funnels mounted over 20 litre plastic containers. Piping, fittings and containers should be made of plastic - the urine is very corrosive metal will corrode badly. The urine diverting pedestal is also another suitable method for collecting urine. These pedestals are commonly used in ecological sanitation projects all over the world. There are variants which allow for squatting as well as sitting. The urine diverting pedestal has a pipe which can be used to convey urine into a storage vessel like a 20 litre plastic drum. Care must be taken to ensure than faecal matter does not enter the urine section. Pedestals mounted over removable buckets can also be used to collect urine - they are useful for women. Potties filled at night in the bedroom can also collect urine a well established method. Urine collectors can also be made which fit into conventional flush toilets, the urine being decanted into plastic bottles. Once the urine is collected - it is stored in plastic containers which are capped before use or processing. 181

2 Collecting and storing urine in bottles is the easiest way for men. On the left urine stored in discarded two litre milk bottles. A funnel placed over a 20 litre plastic container is also effective if well placed in some private location. It is a type of desert lily. On the left a 10 litre bucket is placed beneath a pedestal which helps women to collect urine. On the right a urine collector shaped from a plastic bucket is used to collect urine from a standard flush toilet. Storage Urine can be stored in bottles (2 litre plastic milk bottles for instance) or plastic containers (e.g. 20 litres) for long periods provided they are well capped and the ammonia is not allow to escape. Deposits of the phosphorus and magnesium salts will be deposited however on the base and side walls of the container. Once stored, urine usually turns darker. The exact constituents of urine vary from one person to another. Uses of urine in agriculture There are at least five ways of using urine for the benefit of agriculture. These are: 1. Urine applied to soil without dilution before planting 2. Urine applied to soil without dilution near the young plant, followed by watering 3. Urine applied to soil - diluted with water to the growing plant 4. Urine as an activator for compost. 5. Urine as a medium for fermentation of plant residues 182

3 Examples of using urine to enhance vegetable production in containers. Vegetables like covo, rape, spinach and several other green leafy vegetables can adapt to a wide range of urine applications when applied to containers provided that water is also applied liberally. In fact in the case of vegetables and other plants grown on containers, which hold a relatively small volume of soil, it will always be necessary to apply water regularly to sustain plant health, since the volume of water held in the soil is small. On a hot day, the plants will wilt easily, and require frequent watering. With such a constant throughput of water, diluted urine can be applied as frequently as 3 times per week. For use on containers, urine can be diluted with water at the rates of 3:1 or 5:1 and applied once, twice or three times a week. Where there is a large throughput of water in containers it is best to apply in small doses more often then bigger doses less often. Experience has shown that provided fresh water is added to the basin frequently, green vegetables can withstand the 3:1 and 5:1 applications without harm. Generally the rate of growth of green vegetables is in proportion to the amount of urine applied. However in the longer term, a build up of salt occurs, and there may be an excess of nitrogen which will inhibit the uptake of potassium. For these reasons it is wise to empty the containers of soil treated with urine and remove them to a compost site where the soil can be mixed with other composts and soils and watered without urine application. Thus the soil can be restored and invigorated. A good standard procedure for green vegetables like rape and spinach growing in 10 litre containers is to apply a 3:1 mix twice a week for the first month, with intermediate watering. Reduce this to a 5:1 mix twice a week for the second month with intermediate watering. From then on apply a 5:1 mix once per week with intermediate watering. For tomatoes grown in buckets only apply diluted urine after the first small fruits appear. Then apply 0.5 litres of 5:1, once per week with wood ash (add a tablespoon per week to the bucket soil and watering in). Also for longer term onion (6 months to harvesting) in basins, apply a 3:1 mix twice a week for the first month, with intermediate watering. Reduce this to a 5:1 mix twice a week for the second month with intermediate watering. From then on apply a 5:1 mix once per week with intermediate watering. 183

4 Preparing the urine/water mix General equipment required for applying urine. Various buckets, watering can, rubber gloves and 0.5 litre jug for dispensing the mix. Supply of urine (in 2 litre plastic bottles). A 5:1 mix can be made with 2 litres of urine and 10 litres water. A 3:1 mix can be made with 2 litres of urine and 6 litres of water. Add the 2 litres urine first to a larger (20 litre) bucket, then add 10 litres water from the 10 litre bucket. Apply to the containers from a 0.5 litre jug or similar container. Once or twice a week depending on duration of application. For shorter term (1 3 months) on green vegetables, twice a week with plenty of watering in between. For longer term (3 6 months) the mix should be applied once a week with plenty of watering in between (tomatoes and onion). In some applications additional sources of nutrient are mixed in with the urine/water. Like extra phosphate or wood ash applied at the rate of 5gms per 0.5 litre charge of urine and water (5:1). The wood ash supplies extra potassium, particularly suitable for tomatoes. 184

5 Mixing in extra wood ash to the jug. 5 gms (level tablespoon) ash per 0.5 litres of 5:1 application. The ash helps to make plants more healthy and is good for fruiting. In this case it is being applied to spinach in an experiment. This type of application is particularly good for tomatoes. RAPE Rape is one of the most popular vegetables grown in Zimbabwe. It is used a great deal in relish eaten with maize meal in combination with onion, tomato and meat. It responds well to being grown in containers which are fed urine diluted with water. In this trial, rape was fed diluted urine (3:1) twice a week. The urine application led to a 5 fold increase in harvest after 28days. This is an excellent response to urine. Plant Liquid plant food frequency of application weight harvested Rape water only normal watering 160 gms (9 plants) Rape 3:1 water/urine 0.5 litres 2 X per week 822 gms (9 plants) Left: Photo shows 3 basins (on left) which were water fed and on right 3 basins fed with a 3:1 water/urine mix, twice a week. The effect only became noticeable after 10 days treatment. After 28 days water/urine application the effect is very noticeable (photo on right with water treatment below and urine treatment above. Some of the basins are obscured. Rape yield was increased about 5 times. 185

6 Left: The relative yields of water fed and water/urine fed rape grown on 10 litre basins after 28 days application. The plants have just been harvested for the first time. Right: the same plants almost a month later just before the second crop was harvested. Yellowing and mauve colour on some leaves begin to show after 2 months of urine application at this rate, indicating that the plants are beginning to weaken. This is probably due to over application of nitrogen from the urine. Longer trials like this provide the best indications of the most suitable water/urine treatment under these conditions. A weaker 5:1 application given to the plants once a week may be better in the longer term Spinach Spinach is another popular vegetable in Zimbabwe. Like rape, several harvests can be taken from the same plant over a period of several months. It is ideally suited for growing in containers which are fed diluted urine as shown below. During the first month, the urine application (3:1, twice per week) led to a 3.4 fold increase in harvest after 28days, compared to water fed plants. This is an excellent response to urine. During the second month the urine dose should be reduced to 5:1, twice a week and during the third month and after, the urine dose should be reduced further to 5:1, once per week. 0.5 litres of the diluted urine is applied to each basin per treatment. The plants are watered at all other times. Plant Liquid plant food frequency of application weight harvested Spinach (22plants) Water only normal watering 741gms Spinach (22plants) 3:1 water/urine 0.5litres 2 X per week 2522gms Photos taken of the 16 basin spinach trial. Basins to the left of the green band are urine fed, those to the right water fed only. Photo on left taken on 3 rd December 2003 on the first day of urine treatment. Photo on right taken on 31 st December 2003, 28 days after first urine treatment. The effective of the urine treatment is very positive and very clear to see. Urine fed 3.4 times water fed. 186

7 Left: The total collected harvest of urine treated spinach on the left and water treated spinach on the right after 28 days of urine treatment (3:1, twice per week). Right: plants fed water/urine during their second month are beginning to lag behind plants fed the 3:1 water/urine mix for the first time. The best yield however is being produced by plants shown on the four basins to the right, which have been fed only two applications of the urine water mix and then leaf compost liquor under a mulch of leaves. These signs show that if urine is to be used as a liquid plant food over a prolonged period, the dose should become weaker as the time is extended. For spinach first month 3:1, twice a week; second month 5:1, twice a week; third month and thereafter 5:1, once per week. Extended trials show that the lower dose can maintain spinach output, once the soil has been well fertilised by prolonged and correctly applied urine treatment. 0.5 litres of the diluted urine is applied to each basin per treatment. The plants are watered at all other times. Spinach responds very well to this type of treatment. Onion Onions are well suited to growing in containers and also respond positively to the application of diluted urine. Onions do take a long time to grow, between 6 to 8 months being required between planting seedlings and harvesting. Seeds are best planted during January or February (for Southern Africa) and allowed to grow in seeds trays. They are transplanted into cement basins when about 4 6 weeks old. During this period they can be fed with leaf compost liquor. After transplanting, a weekly application of a urine/water mix (1:5) will help the onion considerably and can begin a week or two after transplanting. Onions need good supplies of nitrogen as well as phosphorus (in the early stages) and plenty of potassium later on. The application of wood ash will help. Planting on a mix of Fossa alterna humus will help, even better if mixed with compost. A good leaf mulch will help the supply of phosphorus and potassium. The application of leaf compost liquor will also help. Up to ten onion can grow in a single 10 litre cement basin. Onion are first grown in seed trays, then transplanted to basins. These onion were fed a 3:1 water/urine mix, once a week. They were planted as seedling on 17 th May and reaped about 6.5 months later on 27 th October An average of 1 kg of onion was reaped from each of ten jars planted. The number of plants varied between 5-9 plants at harvest with weights per basin varying from 0.7kg to 1.3 kg. The growth was improved by the application of a mulch made of leaves. This reduced weeds and also provided some nutrients as well as reducing water loss from the soil. The basin and urine method appears to suit onion. 187

8 Some very good looking onion can be grown in cement basins with the help of a water/urine feed. Here two prize specimens! Onion seeds are best planted early in the year, late January or February being good times, so they can be transplanted into containers towards the end of the rains in April. The healthy onion on the right was harvested in early September after 6 months of water/urine treatment in a 10 litre cement basin. 0.5 litres of a 5:1 mix of water had been applied once a week for all that period together with intermediate watering. Such a result reveals the usefulness of urine as a plant food. TOMATO Tomato seedlings will grow in unmixed neat Fossa alterna humus, but grow better in a 50/50 mix of the humus and garden/leaf compost. The addition of the leaf compost makes the final mix more crumbly and well drained. The soil should be rich in phosphorus to start to help the plants grow sturdy roots and early shoots. When growing in containers most hungry feeders (like tomato, onion and other vegetables) will require additional feeding and in organic farming this is often supplied in liquid form. Diluted urine can be useful, if applied with care with the addition of wood ash (to enhance potassium) and also liquid feed from composting leaves. However diluted urine should not be applied until the flowers have formed and the early small fruit is starting to grow. If too much nitrogen is given (such as with too much urine application), the leaves will grow abundantly with less fruit production. After fruiting has begun more nitrogen (from urine) and particularly potassium (from wood ash) can be applied for the best yields. Tomatoes do require a lot of attention and special treatment to do their best. For more information on growing tomatoes using recycled human excreta, look at the chapter on gardening techniques. Growing tomatoes in bags and buckets 188

9 More examples of plants grown with the help of urine Young mulberry cuttings once established respond well to a dose of 5:1 water and urine weekly (0.5 litres per plant). The same applies to the mint plant on the right growing in a 10 litre bucket. Passion fruit also responds very well to the application of urine and water. In a 30 litre pot this passion fruit is fed with 1 litre of a 5:1 mix of water and urine weekly. The petrea tree is also fed a 5:1 mix of urine and water (10 litres every month). Celery also responds well to a 5:1 mix of urine and water (0.5 litres per container weekly). This large radish was fed in the same way. 189

10 MAIZE Urine can have a significant effect on maize growth. In the fields urine can be applied neat to soil before planting in beds. It can also be applied neat in hollows made near the growing plant. Neat urine applied to maize fields at the rate of 100mls per plant per week and then diluted with rain water, led to increases of cob weight between 28 and 39% compared to watered fed plants only in trials on the Marlborough vlei in Harare (See bibliography Ecological Sanitation in Zimbabwe vol. IV) Growing maize in containers Maize trials on the fields using urine. Maize is rarely if ever grown in containers, but the effect of the growth of maize in containers when fed urine is stunning. Maize plants are hungry feeders and like a lot of nitrogen The application of a 3:1 mix of water and urine, once or twice or even three times a week on maize grown in 10 litre containers is particularly effective. For small scale maize or sweet corn production, this method may have application. It is also an effect way of demonstrating the effect of converting the nutrients held in urine into vegetative growth of valuable plants. Left: The maize plant on the right is being fed with a 3:1 mix of water and urine (0.5 litres) three times per week. The maize on the left is irrigated with water only. The difference is striking. Right: Urine treatment also improves maize cob yield significantly. The total yield of cobs from maize planted in three 10 litre basins is shown. On the left the maize was fed 1750mls urine per plant over the 3.5 month growing period, resulting in a crop of 954 gms. A reduced crop resulted from reduced input of urine (middle). Maize plants on the right were irrigated with water. This is a very high rate of urine application, but one happily accepted by the maize plants in the containers which were irrigated frequently with water to keep the maize plants healthy. 190

11 Growing maize with the help of toilet compost and urine on poor sandy soils Maize is the single most important crop in Southern and Eastern Africa being the staple diet for hundreds of millions of people in the sub- region. And large numbers of these people live on poor sandy soils, which cannot support a good crop of maize without fertiliser, or adequate quantities of cow manure. For those living in the urban areas and peri-urban fringes, cow manure may be scarce and commercial fertiliser too expensive to buy. Yet millions of people eek out a living in these settlements by growing their own crops of maize and vegetables every year in back yard plots and gardens close to the home. It is a means of self survival in conditions which are often harsh and where malnutrition abounds. The simple question is then asked - can the use of toilet compost and urine, in combination, significantly increase the production of these backyard gardens, and thus make the effort worthwhile. The work reported earlier in this chapter shows clearly how maize production can be enhanced considerably by the application of urine. Maize is a greedy feeder and requires considerable amounts of nitrogen to grow at its best and provide generous harvests. It also requires adequate amounts of phosphate in its early stages to enhance the growth of the root system and the young stem above ground. Normally, if commercial fertilizer is used a single maize plant is given at least 10gms of a mix of nitrogen, phosphorus and potassium in the ratio 1:2:1 (in Zimbabwe this fertilizer is known as Compound D). The elevated phosphorus content helps early root formation and shoot growth. At 4 weeks (or when the plant is at knee height) a further application of 10gms or more of ammonium nitrate is given. This is normally sufficient to carry the plant through its full vegetative growth. These two applications of granular slow release commercial fertilizer offer each plant between 4 and 5 gms of nitrogen, about the same as is found in one litre of urine produced by people who have a low protein diet - sadly the great majority who live in Zimbabwe. Very often an extra dose of ammonium nitrate is given when the young maize cob or cobs start to grow. This is thought to be an important application where bumper crops are required. It is generally known that the more nitrogen is applied the better the harvest. What is important is that the nutrients supplied first help the root and early shoot system, with the bulk of the nitrogen being applied to assist vegetative growth and cob formation during the life of the plant. So it helps if this application of nitrogen can be extended into the period of grain filling when the cobs themselves are growing. Grain filling normally starts about 10 weeks after the seed is planted. The cobs continue to gain in weight from 4 to 6 weeks after their formation. Good rains or adequate water supply are very important during this phase. These requirements are well served by first planting the maize seed in a plug of toilet compost made in the soil. This compost is well aerated and contains humus a requirement particularly useful for sandy soils. It also provides a supply of phosphorus and some nitrogen, suitable for the germination and early growth of the plant. Toilet compost also makes an excellent potting soil and is an ideal medium for the germination of seeds of many kinds. This compost is particularly valuable where local topsoil, like fine sandy soil, may not provide the ideal medium for germination. About 500 gms of toilet compost are applied per planting station. This is about one pea tin full. 191

12 A field trial in Epworth near Harare Epworth is a large peri-urban settlement of about 200,000 people close to Harare. It was chosen as an experimental site to demonstrate the effectiveness of urine as an alternative to commercial fertilizer for maize production because it is characteristic of the conditions under which millions of people live both in peri-urban and rural areas in Southern Africa. Natural Epworth topsoil is sandy, porous, almost without nutrients and applied nutrients can easily be lost by leaching during heavy storms. Without commercial fertilizer or manure, maize and vegetable crops are generally very poor on soils of this type. However despite this backyard soil in Epworth is characteristically patchy with variable nutrient level. This is because over the years sections of land have been fertilized with manure and compost, particularly in delineated vegetable gardens. Also there is some fertilization of maize crops for those who can afford to buy. So there is some carry over of nutrients from year to year. In the experiment, the field was dug and levelled beforehand and on planting day hundreds of small holes were dug in lines and rows ready for planting. 125mls of urine (which had been collected in 20 litre plastic containers previously) was applied to each planting station. This was followed by a 500gm plug of toilet compost. Two seeds were planted in the compost and covered over. The field is prepared by digging and holes are made 30cms apart in rows 90cm apart. The 20 litre drum of collected urine is shaken up (to mix the phosphorus) and added to a 20 litre bucket. Date Using a dispenser, 125mls of urine is added to every hole 192

13 This is followed by one pea tin full (500gms) of toilet compost taken from the Fossa alterna or other composting toilet. Two seeds are then planted in the compost and pressed down and then covered with the topsoil. If seeds are in short supply then a single seed can be planted. Over 90% of registered maize seed will germinate. Another seed can be planted if a single seed does not germinate. The seeds are pressed into the compost and covered with topsoil awaiting the rains On the left the field site at Epworth showing the Fossa alterna from where the humus was taken. Picture on right taken 2 nd December 2004 when the maize had started to grow. 193

14 If two seeds had germinated, which was normally the case, one was removed and planted elsewhere. Adding the second 125mls application of urine to the young plant. Photos taken on 3 rd January On the left photo the plants on the lower left were not treated with urine. Plants in mid picture and right had been treated. The difference is obvious. On the right photo, the lush growth of plants following urine treatment is clear to see. Digging small hole near to plant step prior to urine application. On the right, the urine has been stored in the 20 litre plastic container. It is poured into a bucket and then dispensed with the small pill bottle dispenser next to each plant. 194

15 Applying the 125mls of urine in a hollow next to the plant. Best to cover over after application. 125mls are added weekly to each plant, the last 2 applications are added fortnightly to make a total of 1000mls for each plant. This is equivalent to around 5gms nitrogen. 17 th January 2005, first signs of tassel (left) and cob (right). 195

16 This photo was taken 31 st January 2005 at the time when the last of the urine was applied. In the treated area (right) the growth of maize has been good and cobs are already forming. On the left the untreated area shows smaller and paler plants with little cob formation. Healthy lines of maize with healthy cobs growing in treated zone on 31 st January On the right two cobs are growing, revealing that the urine application as per the schedule is adequate. On this day the final 125mls of urine was added making the total application one litre per plant. The first application was made at planting, the second to 6 th application a week apart. The last two applications were spread a fortnight apart. This regime carries the application of urine nitrogen into the grain filling stage. 196

17 Final observations and cob measurement In the current trial a small existing backyard maize field was chosen which also housed an ecological toilet (Fossa alterna). 200 maize were planted in 500gms of toilet compost and treated with a total of one litre urine during the vegetative and grain filling stages (as indicate above). A further 40 plants were not treated with compost or urine. 40 additional plants were treated with standard fertilizer. At harvesting and for comparison a small sample of cobs was also taken from an adjacent field where no treatment of any type had taken place. Seed was planted in mid November and cobs harvested in mid March a period of 4 months. Results Section No. Plants Mean cob Equivalent Wt. (gms) grain wt.(gms). Untreated (field 2) Untreated (field 1) Treated: commercial fertilizer (field 1) Treated: urine (1 litre per plant field 1) There was much variation between individual plants in all sections (apart from field 2) of the trial, mainly due to the variable existing nature of the soil even within each section of the experimental field, and probably due to earlier applications of manure, compost or fertilizer. This variation is characteristic of such fields and gardens. This variation was less evident in the urine fed section, where the treatment had a significant effect on maize growth and cob size with more consistently larger cobs. Overall mean cob weight was increased by 1.76 times (138gms to 242gms) by urine application when compared to the untreated section. When plotted against grain weight, this increase in cob weight (X 1.76) represents a doubling in the yield of grain. When plotted on a graph, a 138gm cob yields 75gms of freshly stripped grain compared to the larger 243gm cob which yields 148gms of grain. The relatively high mean for untreated maize (field 1) was probably due to a sub-surface bed of manure or compost in one patch of the control zone which promoting healthy growth of a few plants making up 27% of the total cob weight in this section. The mean cob weight of urine treated maize (243gms) was about three times the mean cob weight (82gms) of sample cobs taken from another untreated field nearby, more typical of the area, where cob weights were more consistently poor. In terms of grain weight this is an increase of four times. The urine was produced by the family itself and probably contained about 5gms/litre nitrogen, approximately the same as the nitrogen applied with commercial fertilizer. Residents in the area were impressed by the effect of urine treatment, which was plainly visible and cost nothing, but did require effort on the part of the householder. Put in simple terms The application of 1 litre of urine per plant, applied in small lots (125mls) over the growth period, doubled the grain yield of maize growing on poor sandy soil compared to unfed plants. 197